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Chapter 1. Introducing Environmental Science and Sustainability. Overview of Chapter 1. Human Impacts on The Environment Population, Resources and the Environment Environmental Sustainability Environmental Science Assessing Environmental Problems. The Environment (Earth).
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Chapter 1 Introducing Environmental Science and Sustainability
Overview of Chapter 1 Human Impacts on The Environment Population, Resources and the Environment Environmental Sustainability Environmental Science Assessing Environmental Problems
The Environment (Earth) Life has existed on earth for 3.8 billion years Earth well suited for life • Water covers ¾ of planet • Habitable temperature • Moderate sunlight • Atmosphere provides oxygen and carbon dioxide • Soil provides essential minerals for plants But humans are altering the planet; not always in positive ways
Human Impacts on the Environment Increasing Human Numbers
Human Impacts on the Environment Most populous countries: 1) China 1,343,239,923 2) India 1,205,073,612 3) United States 313,847,465 4) Indonesia 248,645,008 5) Brazil 199,321,413 Source: CIA.gov, Global Population Profile: 2012 estimates
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Population Globally, 1 in 4 people lives in extreme poverty Difficult to meet population needs without exploiting earth’s resources
Leads to . . . Human Impacts on the Environment Poverty : • per capita income of less than $1 a day • 1.2 billion worldwide currently live at this level Inadequate health care Unsanitary water Poor nutrition Lower life expectancy
Population, Resources, and the Environment The contrast between less developed and highly developed countries is great:
Gap Between Rich and Poor Highly Developed Countries (HDC) • Complex industrialized bases, low population growth, high per capita incomes • Ex: US, Canada, Japan Less Developed Countries (LDC) • Low level of industrialization, very high fertility rate, high infant mortality rate, low per capita income • Ex: Bangladesh, Mali, Ethiopia
Renewable, but only when managed in a sustainable way Population, Resources, and the Environment Types of resources:
Population, Resources, and the Environment Resource Consumption: • because of our greater consumption rates, 1 US child has the environmental impact of 12+ children in less developed countries.
Overpopulation People overpopulation • Too many people in a given geographic area • Problem in many developing nations Consumption overpopulation • Each individual in a population consumes too large a share of the resources • Problem in many highly developed nations
Ecological Footprint The average amount of land, water and ocean required to provide that person with all the resources they consume
Environmental Impact Affluence per person I = P A T Environmental effect of technologies Number of people Population, Resources, and the Environment IPAT Model
Environmental Sustainability Sustainability: Stewardship
Environmental Sustainability The ability to meet current human need for natural resources without compromising the needs of future generations Requires understanding: • The effects of our actions on the earth • That earth’s resources are not infinite
Environmental Sustainability Sustainability and the Tragedy of the Commons Garrett Hardin
Sustainable Development Economic development that meets the needs of the present generation without compromising future generations
Environmental Science • Interdisciplinary study of the interconnected problems associated with the environment. • Heavily leans upon ecology.
Environmental Science Controls and Variables in Experimental Design Variable: • factors influencing processes being examined. • hypothesis examines ONE variable, holding others constant. • This is the experimental group. • Control group : • examined variable is left unaltered
Environmental Science • Hypothesis: Burning will increase frequency of prairie wildflowers. Which is the control group?
Earth As a System System • A set of components that interact and function as a whole Global Earth Systems • Climate, atmosphere, land, coastal zones, ocean Ecosystem • A natural system consisting of a community of organisms and its physical environment System approach to environmental science • Helps us understand how human activities effect global environmental parameters
Earth Systems Most of earth’s systems are in dynamic equilibrium or steady state • Rate of change in one direction equals that in the other Feedback • Change in 1 part of system leads to change in another • Negative feedback- change triggers a response that counteracts the changed condition • Positive feedback- change triggers a response that intensifies the changing condition
Environmental Science How does the view of a Theory differ between scientists and the public?
Controls and Variables in Experiment Variable • A factor that influences a process • The variable may be altered in an experiment to see its effect on the outcome Control • The variable is not altered • Allows for comparison between the altered variable test and the unaltered variable test
Inductive and Deductive Reasoning Deductive Reasoning • Proceeds from generalities to specifics • Adds nothing new to knowledge, but makes relationships among data more apparent • Ex: • GENERAL RULE: All birds have wings • SPECIFIC EXAMPLE: Robins are birds • CONCLUSION (based on deductive reasoning): All Robins have wings
Inductive and Deductive Reasoning Inductive Reasoning • Used to discover general principles • Seeks a unifying explanation for all the data available • Ex: • FACT: Gold is a metal heavier than water • FACT: Iron is metal heavier than water • FACT: Silver is a metal heavier than water • CONCLUSION (based on inductive reasoning): All metals are heavier than water • Conclusions reached with inductive reasoning may changed with new information
Five Stages to Addressing An Environmental Problem Five steps are idealistic • Real life is rarely so neat Following Slides are Case Study Using the Five Stages
Assessing Environmental ProblemCase Study: Lake Washington Large, freshwater pond Suburban sprawl in 1940’s • 10 new sewage treatment plants dumped effluent into lake Effect = excessive cyanobacteria growth that killed off fish and aquatic life
Assessing Environmental ProblemCase Study: Lake Washington Scientific Assessment • Aquatic wildlife assessment done in 1933 was compared to the 1950 assessment • Hypothesized treated sewage was introducing high nutrients causing growth of cyanobacteria Risk Analysis • After analyzing many choices, chose new location (freshwater) and greater treatment for sewage to decrease nutrients in effluent
Assessing Environmental ProblemCase Study: Lake Washington Public Education/Involvement • Educated public on why changes were necessary Political Action • Difficult to organize sewage disposal in so many municipalities • Changes were not made until 1963! Evaluation • Cyanobacteria slowly decreased until 1975 (gone)
Addressing Environmental Problems Case in Point: Lake Washington RESULTS
Addressing Environmental Problems Case in Point: Lake Washington RESULTS